This invention relates to an ammunition belt apparatus for propellant cartridges, rimfire cartridges, or the like, with a flexible coilable strip of a metal, a synthetic resin, or the like having spaceapart apertures and associated tubular casings into which the propellant cartridges, rimfire cartridges, or the like can be placed from the side of the belt facing away from the casings, in the manner of a press fit, until abutment is obtained with the rim of the cartridge laterally projecting in the zone of its base. This invention also relates to the method of making the above-mentioned apparatus.
An ammunition belt -- also called cartridge magazine -- is known from DOA (German Unexamined Published Application) No. 1,678,396 for stud drivers driven by powder force. This ammunition belt with recesses and associated tubular casings is manufactured in one piece from a synthetic resin by the injection molding method. The propellant cartridges are pushed into the recesses and the adjoining casings and held therein by a press fit. For firing purposes, the cartridges are not removed from the ammunition belt but rather are introduced together with the casing into the cartridge chamber of the stud driver and, after firing, again removed from the chamber together with the casing and/or the ammunition belt. Thus, the cartridges remain in the cartridge belt during feeding to the firing tool, during firing, and during removal from the firing tool. This makes it possible to construct the firing tool in a relatively simple manner.
However, the conventional cartridge belts depicted in the DOA No. 1,678,396 are not entirely satisfactory in practice because they have only a limited length, due to the manufacture by the injection molding process, and because they are too expensive in their manufacture, since they can be used only once.
The present invention is based, at least in part, on the problem of avoiding the above-mentioned disadvantages, i.e. constructing an ammunition belt for propellant cartridges, rimfire cartridges, or the like so that it can be produced with practically any desired length with a minimum of expense, in order to still further simplify the work with firing tools especially for commercial usage, for example stud drivers, cattle stunning devices, or appliances for the deformation of materials.
According to the present invention, the above-mentioned problems are solved, for a cartridge belt of the type mentioned in the foregoing, by providing that the belt or strip part of the belt and the casings are produced separately from each other and are joined by means of the inserted propellant cartridges, rimfire cartridges, or the like, by enclosing the strip between the rims of the cartridges and the casings. This arrangement makes it possible advantageously to produce the belt, for example of a synthetic resin, by means of extrusion in any desired length -- so to speak in an endless form -- and then to perforate the belt continuously to produce holes distributed at uniform spaces along its length. The casings manufactured separately therefrom, for example, by the injection molding method, are simply placed on the propellant cartridges, rimfire cartridges, or the like which have been pushed through the perforations. In this connection, the radial play between the shell or cartridge case and the casing is dimensioned so that both are securely joined by a frictional connection in the manner of a press fit, and thus are also simultaneously connected with the belt.
In another preferred embodiment of the present invention, the strip for the ammunition belt is maufactured of metal rather than a synthetic resin, the production of the perforations being likewise effected by continuous punching as described above for the extruded synthetic resinous strip. The cartridge shell or cartridge case is connected with the separately manufactured casings in the same manner as in the plastic (synthetic resinous material) strip.
In another advantageous preferred embodiment of the invention, the casings are additionally provided with an external annular groove in the zone of their ends on the side of the strip so that they can be inserted in the perforations of the strip by a snap connection with corresponding annular tongues provided at the perforations of the strip. Since the inserted propellant cartridges, shells, or the like effect an additional radial contact pressure between groove and tongue, it is possible in this embodiment to increase the strength of the connection between the strip and the casings considerably, if this should prove appropriate or advantageous in individual cases. According to another suggestion of this invention, the provision can furthermore be made to equip the casings, in the zone of their ends on the strip side, with at least respectively one slot extending in the longitudinal direction of the casings, in order to enhance the elastic deformation of the end of the casings occurring when the casings are pressed into engagement with the annular tongues at the perforations.
The feature of this invention of manufacturing the belt strip and the casings separately and then joining them subsequently in a simple manner offers, however, still another considerable advantage. The cartridge belt strip, manufactured with a relatively great length, must be coilable, on the one hand, for reasons of compactness, so that the belt strip must be correspondingly elastic and/or flexible in order to be easily wound and unwound. On the other hand, the casings which are introduced together with the shells, cartridges, or the like into the chamber of the respective firing device form part of this chamber and also take over a part of its function. In order to ensure the flawless firing and also the ejection of the shells, cartridges, or the like, the casings must safely withstand the thermal and mechanical stresses in the chamber of the firing device. The requirements to be met by the properties of the material of the belt and the casings are accordingly different.
These differing requirements can be satisfied in an extremely simple and advantageous manner, according to another suggestion of this invention, by manufacturing the belt from a readily flexible material, whereas the casings are produced from a material having a higher strength, a higher thermal stability, and a lower fluidity or flow property. It is advantageous, in this connection, to make the belt from polyethylene or polypropylene, whereas the casings are preferably produced from polyamide, polycarbonate, or cellulose acetate. However, it is, of course, also possible according to the present invention to utilize combinations different therefrom, i.e., for example to manufacture the strip from polyamide and the casings from polypropylene, if this should prove advantageous in a certain case. The geometric shape of the casings is determined, by the way, in accordance with the configuration and the dimensions of the cartridge, shell, or the like, the chamber of the firing device, etc. so as to accommodate press-fitting of the casings over the cartridges and so as to fit the firing device chamber.
According to further embodiments of this invention, the cartridge belt is constructed for use with caseless propellant charges. These caseless propellant charges can be formed, for this purpose, for example with a laterally projecting rim integrally formed at the rear end, so that the strip is held between this rim and the casings pushed with frictional connection onto the propellant charges. With this arrangement, unless the casings are joined to the strip of the belt in some other, additional manner, they are detached therefrom after the reaction of the propellant charges and are then ejected toward the rear by the residual pressure of the powder gases still present in the chamber of the firing device, before the subsequent propellant charge is fed into the chamber, so that the next propellant charge with its casing can then be introduced into the chamber.
Instead of producing the caseless propellant charges with a projecting, integrally formed rim, it is also contemplated, according to another embodiment of this invention, to provide the rim of the propellant charges necessary for the connection with the strip by an annular mounting element pushed onto the charges. This mounting element can be joined with the propellant charge, for example, by gluing or also merely by a press fit. In view of a maximally simple and rapid, but yet reliable realization of this connection, a further suggestion of this invention provides to manufacture the mounting element of an elastically deformable material and to hold the element at the propellant charges by a frictional connection. For this purpose, the mounting element can be manufactured, for example, from an elastic rubber or also from thermoplastic synthetic resins, such as, for example, polyethylene or polypropylene. This construction offers the additional advantage, moreover, that the mounting element is simultaneously effective as a rearward seal for the chamber of the firing device, so that the powder gases cannot escape unduly toward the rear and perhaps ignite the propellant charges still outside of the firing device. In order to effect a maximally safe frictional mounting of the caseless propellant charges, the casings are preferably also manufactured from an elastically expandable material.